Balfour is scheduled for arthroscopic surgery on his right knee Thursday afternoon. The A's made the announcement that the right-hander is expected to miss four to six weeks, and decided to have the procedure now with the hopes of returning for the start of the season.
Posted: Feb. 14, 2013 2:35 PM ET
The 35-year-old Balfour went 3-2 with a 2.53 ERA and 24 saves last season for the AL West champions. The A's exercised their $4.5 million contract option for the Australian reliever shortly after the team lost in a five-game division series to the Tigers.